Highly radioactive noble gas that is used mainly in medicine (destroying cancerous tumors) and in predicting earthquakes.
xenon
Rarest gas in the atmosphere; it is used mainly in discharge lamps, photoflash bulbs and lasers.
krypton
Noble gas that is used in some incandescent lamps and in photography.
argon
Most abundant of the noble gases; it is used especially in incandescent lamps and in welding (protective gas).
neon
Noble gas that is used mainly in lighting (billboards, television tubes and fog lamps), but also as a liquid coolant.
helium
The lightest of the noble gases is noncombustible and abundant in the stars; it is used especially in inflating aerostats (such as balloons and dirigibles).
